Legume Research
Web of Science
  • Year: 2025
  • Volume: 48
  • Issue: 4

Candidatus phytoplasma australasia associated with alfalfa witches’ broom: Symptomatology, quantitative loss, qualitative loss and molecular characterization

  • Author:
  • H.S. Mahesha1,*, M.C. Keerthi1, Ravi Prakash Saini1, N. Manjunatha2, L. Manjunatha3, K.V. Shivakumar4, M. Gurivi Reddy5, K. Sridhar6, V.K. Yadav1
  • Total Page Count: 7
  • Page Number: 616 to 622

1ICAR-Indian Grassland and Fodder Research Institute, Jhansi-284 003, Uttar Pradesh, India

2ICAR-National Research Centre on Pomegranate, Solapur-413 255, Maharashtra, India

3ICAR-Indian Institute of Pulses Research, Kanpur-208 024, Uttar Pradesh, India

4ICAR-Central Research Institute for Jute and Allied Fibres, Sunnhemp Research Station, Pratapgarh-230 001, Uttar Pradesh, India

5Sri Venkateswara Agricultural College, Acharya N.G. Ranga Agricultural University, Guntur, Tirupati-517 502, Andhra Pradesh, India

6Southern Regional Research Station, ICAR-Indian Grassland and Fodder Research Institute, Dharwad-580 005, Karnataka, India

*Corresponding Author: H.S. Mahesha, ICAR-Indian Grassland and Fodder Research Institute, Jhansi-284 003, Uttar Pradesh, India, Email: hsmaheshhunsur@gmail.com

Online published on 22 July, 2025.

Abstract

Alfalfa, Medicago sativa L. is the most important and widely grown leguminous fodder crop in temperate and tropical regions of the world. The production of alfalfa crop is limited by several biotic stresses, among which witches’ broom disease (AWB) was reported to cause significant economic losses.

The phytoplasma infected alfalfa plants were collected from a central research farm, ICAR-IGFRI, Jhansi, U.P. Qualitative parameters such as crude protein content, acid detergent fibre and neutral detergent fibre were estimated in diseased and healthy plants. Phytoplasma universal primer (P1/P7) and nested primer (R16mF2/R16mR1) were used for the molecular characterization of AWB infected plants and phytoplasma infected, Parthenium hysterophorus.

The incidence of AWB disease ranged from 8-10%. The quantitative analysis of disease plants showed reduced plant height (-35%), fresh weight (-46.89%) and dry weight (-50.08%) compared to healthy plants. The diseased plant recorded low crude protein content (-21.38%) and higher dry matter content (+0.68%), acid detergent fibre (+33.72%) and neutral detergent fibre (+13.06%). The association of phytoplasma in diseased alfalfa and parthenium samples was confirmed by using P1/P7 and R16mF2/R16mR1 primer pair and Blastn analysis shared 99.6-100% similarity with ‘Candidatus Phytoplasma australasia’ belongs to the 16Sr group II-D.

Keywords

Alfalfa, Ca. Phytoplasma australasia, Crude protein, Witches’, Broom